I have the EC powder measure quick connect on both of my 650's. It works great and makes emptying the powder quick and easy. No hunting for the correct allen wrench. The Dillon is designed to change the tool heads, leaving the dies settings unchanged. Setting the dies is always time consuming. Ebay has lots of aftermarket tool heads for sale.
I solved the primer change over problem by just setting up one 650 for small pistol primers and the other 650 for large pistol primers. Ok, not the cheapest solution but it's quick and simple.